This is not yet updated in the the handbook -- but the
8.0-RELEASE-I386-memstick.img
is an new addition to the FBSD install media world. This is a DD copy of an fixit sysinstall running system. Its very large is size. Three times larger then the disc1.iso. I tested this memstick.img and was unhappy with how long it took to download. In release 8.0 the sysinstall process was updated and now has USB support as option to select where the install files come from.

The thing you have to keep in mind is that most bios older that 2008 do not have option to boot from USB sticks or can only boot from a few different vendor USB sticks. Some vendor sticks will not be reconized by your bios as bootable. Testing the USB stick is the only way to find out if its bootable on your PC.

I normally download the disc1.iso and use the following script to load it to a USB flash drive.